Aspen Simulation of Oil Shale Retort off-Gas Cleanup with Venturi Scrubbers

摘要

A significant fraction of the product energy from oil shale retorting is contained in the retort off gas. Most oil shale processes use the retort off gas from plant fuel. The H sub 2 S and NH sub 3 in retort off gas produce too much SO sub 2 and NOX to allow burning without a pollution control system. We used the ASPEN flowsheet simulator to model retort off-gas cleanup by venturi scrubbers. Venturi scrubbers are commonly used to remove particulates from gas streams, but the scrubbing liquid also absorbs some NH sub 3 and H sub 2 S from the gas. The ASPEN venturi scrubber model makes good predictions of the particulate removal efficiency. The ASPEN estimates for H sub 2 S and NH sub 3 absorption are higher than the equilibrium absorption predictions made by a state-of-the-art sour water vapor-liquid equilibrium model, TIDES. The discrepancy probably results from trying to simulate an electrolyte system with a vapor-liquid equilibrium model that is designed for molecular systems. The simulation indicates that a venturi scrubber may absorb enough NH sub 3 to serve as the primary NH sub 3 removal system. The H sub 2 S absorption is quite low, however, and some other process is needed to remove the H sub 2 S. 17 references, 6 figures, 3 tables. (ERA citation 09:025382)